1. Field of the Invention
The present invention relates generally to diagnostic testing in a data processing system, and more specifically, to a non disk-based diagnostics procedure for use in a data processing system.
2. Description of Related Art
The complexity of modern-day data processing systems provides many benefits to the user. However, the variety and complexity of different components in the system can give rise to problems in diagnosing the source of a problem in the system. Accordingly, it is an ongoing requirement to provide for diagnostic testing of data processing systems, especially systems such as, for example, network file servers where a problem can lead to significant network downtime and/or loss of user data. Comprehensive diagnostic testing involves exercising the operation of many different components of the system in order to determine the cause of a fault.
The most common type of diagnostics is disk-based where the diagnostics program is stored on either a hard disk drive or a floppy disk drive. The diagnostics program is retrieved from the disk drive and executed on the computer under the control of an operation system. One limitation of disk-based diagnostics programs is that in order to run the diagnostics program, the computer needs functioning components such as the disk drive, a keyboard, a central processing unit (CPU), a memory and a monitor. Therefore, disk-based diagnostics programs can only be used when the necessary components of the computer are functioning. However, it is commonly the case that the faults to be diagnosed prevent the computer from booting (initiating start-up operations) in the first place.
In order to diagnose such faults, therefore, a second type of diagnostics program is incorporated in the computer firmware. This type of diagnostics is referred to as a ROM-based diagnostics program because the diagnostics program is stored in a read-only memory (ROM), or similar type of non-volatile memory. One well known type of ROM-based diagnostics program used in personal computers is called a power-on self test (POST) diagnostics program which is stored in the system BIOS (basic input output system). The POST is executed each time the computer powers-on in order to check the presence and operation of various critical computer components.
The POST is, however, limited in its capabilities for two main reasons. First, as it executes at every power-on, it is designed to have a rapid execution time in order that the computer user is not significantly delayed before the computer is available for use. Second, the space available in system ROM BIOS for the POST diagnostics program is severely limited.
An example of a ROM-based diagnostics program is described in U.S. Pat. No.: 5,398,333, issued Mar. 14, 1995, entitled "Personal Computer Employing Reset Button To Enter ROM-Based Diagnostics", by Schieve et al. The method employed by Schieve et al. comprises storing a diagnostics routine in ROM, monitoring the status of a reset button coupled to the personal computer and executing the diagnostics routine if the reset button is pressed twice within a predefined period of time.
One problem common to the prior art disk-based and ROM-based diagnostics programs is the need for the person initiating the diagnostics program to be physically located at the computer to be tested, either to insert a diagnostics diskette or, in the case of the system disclosed by Schieve et al., to press the computer reset button. If the person initiating the diagnostics needs to test a number of systems which may be at different locations, the process can be substantially time-consuming and inefficient.
In view of the disadvantages of the prior art device described above, it can be appreciated that it would be desirable to provide an improved technique for performing diagnostic testing of a data processing system, such as file server system, which overcomes these disadvantages.